1. Indoor device or a protective way outdoor applications.
2. The outdoor unit, such as wind, sand, rain, sunshine erosion;
3. With flammable, explosive gas or dust environment;
4. The humid tropics, dry tropics environment;
5. Pipeline medium temperature above 450 ℃;
6. Environmental temperature below 20 ℃ below;
7. Vulnerable to water or flooding;
8. Radioactive substances (nuclear and radioactive material test device) environment;
9. The ship or dock on (with salt spray, mold, moisture) of the environment;
10. Has the intense vibration occasions; Easy to fire situation;